An aircraft landing guidance system and method based on microwave radiation passive imaging

Abstract

This invention provides an aircraft landing guidance system and method based on microwave radiation passive imaging, belonging to the field of aircraft technology. It includes: a synthetic aperture microwave radiation imaging system acquiring synthetic aperture microwave radiation images of the scene to be observed; a GPS positioning system providing aircraft position information; an inertial navigation system providing aircraft attitude information; a 3D scene model storage device storing an airport 3D scene model; a processing unit generating real-time guidance image information based on the synthetic aperture microwave radiation images, aircraft position information, aircraft attitude information, and the airport 3D scene model; and a head-up display showing the real-time guidance image information. This invention utilizes the advantages of microwave radiation passive imaging, such as strong cloud and fog penetration and low susceptibility to ground clutter, to provide aircraft with a surrounding environment for approach and landing in low-visibility weather, further improving the safety and timeliness of aircraft landing guidance in low-visibility weather.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and in particular to an aircraft landing guidance system and method based on microwave radiation passive imaging. Background Technology

[0002] In the aviation industry, a significant challenge lies in the logistical delays, widespread flight disruptions, and even major public safety incidents caused by low visibility weather, resulting in substantial economic losses and casualties. Despite the availability of advanced ground guidance systems and airborne equipment, low visibility remains a major threat to aircraft approach and landing safety, and is a primary factor contributing to serious aviation accidents. Therefore, aircraft approach and landing in low visibility conditions has always been a key focus in aviation development, and how to guide aircraft safely to approach and land under low visibility conditions is of significant practical importance.

[0003] Currently, the main systems used internationally to ensure aircraft approach and landing in low visibility conditions are the Instrument Landing System (ILS) and the Microwave Landing System (MLS). Although ILS or MLS provide guidance in low visibility, they cannot currently replace the challenge of visual landing for pilots during aircraft approach and landing in low visibility. The core solution to this problem is "visualization," that is, enabling pilots to see a realistic and reliable visual image of the aircraft's surrounding environment in low visibility conditions. To this end, the international civil aviation community has conducted extensive and in-depth research around this goal, successively proposing and developing solutions such as Enhanced Vision Systems (EVS) and synthetic vision systems.

[0004] To address the need for safe approach and landing guidance for aircraft in low-visibility conditions, research began in the 1990s on airborne active infrared or microwave imaging systems for low-visibility weather. These systems can provide pilots with real-time dynamic images in low-visibility environments to assist them during approach and landing. However, existing airborne active infrared or microwave methods for obtaining infrared or active microwave images for aircraft approach and landing still have many shortcomings. Infrared detection has limited penetration capabilities in dense fog, and active microwave imaging is susceptible to ground clutter interference. Summary of the Invention

[0005] This invention provides an aircraft landing guidance system and method based on microwave radiation passive imaging, which solves the defects of existing technologies when aircraft approach and land in low visibility conditions using landing systems or infrared microwave active imaging technology, such as limited penetration ability, susceptibility to interference, resulting in insufficient clarity of the generated landing guidance images and too many interference factors.

[0006] In a first aspect, the present invention provides an aircraft landing guidance system based on microwave radiation passive imaging, comprising:

[0007] The integrated processor, along with an integrated aperture microwave radiation imaging system, a GPS positioning system, an inertial navigation system, a three-dimensional scene model memory, and a head-up display, all connected to the integrated processor.

[0008] The integrated aperture microwave radiation imaging system acquires integrated aperture microwave radiation images of the scene to be observed;

[0009] The GPS positioning system provides aircraft location information;

[0010] The inertial navigation system provides aircraft attitude information;

[0011] The 3D scene model storage device stores the 3D scene model of the airport;

[0012] The integrated processor generates real-time guidance image information based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model;

[0013] The head-up display shows the real-time guidance image information.

[0014] Secondly, the present invention also provides an aircraft landing guidance method based on microwave radiation passive imaging, comprising:

[0015] The integrated aperture microwave radiation image of the scene to be observed is acquired by the integrated aperture microwave radiation imaging system, the aircraft position information is determined by the GPS positioning system, and the aircraft attitude information is determined by the inertial navigation system.

[0016] The airport 3D scene model is obtained from the 3D scene model memory and stored.

[0017] The integrated processor outputs real-time guidance image information based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model, and transmits the real-time guidance image information to the head-up display;

[0018] The head-up display shows the real-time guidance image information so that the aircraft can land based on the real-time guidance image information.

[0019] The aircraft landing guidance system and method based on microwave radiation passive imaging provided by this invention utilizes the advantages of microwave radiation passive imaging, such as strong cloud and fog penetration capability and low susceptibility to ground clutter, to provide aircraft with the surrounding environment for approach and landing in low visibility weather, further improving the safety and timeliness of aircraft landing guidance in low visibility weather. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the aircraft landing guidance system based on microwave radiation passive imaging provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the integrated aperture microwave radiation imaging system provided by the present invention;

[0023] Figure 3 This is a schematic diagram of the antenna array in the integrated aperture microwave radiation imaging system provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the two-dimensional field of view of the integrated aperture microwave radiation imaging system provided by the present invention;

[0025] Figure 5 This is a flowchart illustrating the aircraft landing guidance method based on microwave radiation passive imaging provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] To address the challenge of safe approach and landing of aircraft in low visibility conditions, the integrated aperture microwave radiation passive imaging technique, based on interferometry, has matured and offers advantages such as wide field of view, high resolution, and instantaneous imaging. Therefore, this invention proposes an aircraft landing guidance system and method based on microwave radiation passive imaging.

[0028] Figure 1 This is a schematic diagram of the structure of an aircraft landing guidance system based on microwave radiation passive imaging provided in an embodiment of the present invention, as shown below. Figure 1 As shown, it includes:

[0029] The integrated processor, along with an integrated aperture microwave radiation imaging system, a GPS positioning system, an inertial navigation system, a three-dimensional scene model memory, and a head-up display, all connected to the integrated processor.

[0030] The integrated aperture microwave radiation imaging system acquires integrated aperture microwave radiation images of the scene to be observed;

[0031] The GPS positioning system provides aircraft location information;

[0032] The inertial navigation system provides aircraft attitude information;

[0033] The 3D scene model storage device stores the 3D scene model of the airport;

[0034] The integrated processor generates real-time guidance image information based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model;

[0035] The head-up display shows the real-time guidance image information.

[0036] Specifically, such as Figure 1 As shown, the aircraft landing guidance system based on microwave radiation passive imaging proposed in this embodiment of the invention includes six modules, namely... Figure 1 The integrated aperture microwave radiation imaging system, GPS positioning system, inertial navigation system, 3D scene model storage, and head-up display are shown in the solid-lined boxes. The dashed-lined modules corresponding to each system module present the functions they provide.

[0037] The integrated aperture microwave radiation imaging system is used to acquire wide-swath real-time microwave radiation images of the scene to be observed, i.e., integrated aperture microwave radiation images;

[0038] GPS positioning systems provide aircraft position information, including longitude, latitude, and altitude; inertial navigation systems provide aircraft attitude information, including pitch, roll, and yaw information.

[0039] The 3D scene model storage is mainly used to store the 3D scene model of the airport. The 3D scene model of the airport is reconstructed by 3D reconstruction technology from optical images of the airport scene taken from different observation angles and then stored in the storage.

[0040] The integrated processor uses the obtained integrated aperture microwave radiation image combined with the aircraft's position information, attitude information and stored 3D scene model to obtain real-time guidance image information for the aircraft (pilot) through fusion and visual enhancement technology;

[0041] A head-up display shows reconstructed real-time guidance images on a screen for the pilot's reference, guiding the aircraft to approach and land.

[0042] This invention utilizes integrated aperture microwave radiation imaging technology to acquire real-time wide-field microwave radiation images of the aircraft's frontal view. It then integrates aircraft position and attitude information with a reconstructed visual image of the aircraft (pilot) based on a 3D airport scene model, providing the aircraft (pilot) with a visual image to guide its approach and landing. This system and method can provide near-real-time, reliable visual images for aircraft approach and landing in low visibility conditions, achieving approach and landing without the need for a ground guidance system.

[0043] Based on the above embodiments, the integrated aperture microwave radiation imaging system includes an antenna array, a receiver channel array, a digital acquisition unit, a digital correlation processor, and an image inversion processor connected in sequence.

[0044] The antenna array outputs microwave radiation signals;

[0045] The receiver channel array receives the microwave radiation signal and generates an intermediate frequency signal;

[0046] The digital acquisition unit performs analog-to-digital conversion on the intermediate frequency signal and outputs a digital signal.

[0047] The digital correlation processor generates a correlation matrix of the scene to be observed based on the digital signal;

[0048] The image inversion processor inverts the correlation matrix of the scene to be observed and outputs the composite aperture microwave radiation image.

[0049] The antenna array includes multiple antenna elements, which together form a cross-shaped antenna array.

[0050] The cross-shaped antenna array includes four antenna arms and one central antenna element, wherein a single antenna arm includes N antenna elements, and the antenna array includes 4N+1 antenna elements, all of which are equally spaced.

[0051] The antenna element is a preset wide-beam circular horn antenna.

[0052] The receiver channel array includes 4N+1 receiver channels, and each receiver channel is connected to a single antenna element.

[0053] The single receiver channel sequentially amplifies, filters, downconverts, amplifies, filters, and demodulates the microwave radiation signal through the radio frequency front end, and outputs the intermediate frequency signal.

[0054] The digital acquisition unit includes 8N+2 analog-to-digital converters, with each pair of analog-to-digital converters corresponding to one receiver channel;

[0055] Each pair of analog-to-digital converters performs analog-to-digital conversion on the I-channel and Q-channel signals of the intermediate frequency signal output from one receiver channel, respectively, to obtain the digital signal.

[0056] The digital correlation processor performs pairwise correlation calculations on the 4N+1 I-channel signals and 4N+1 Q-channel signals output by the digital acquisition unit to obtain the correlation matrix of the scene to be observed.

[0057] The image inversion processor determines a two-dimensional instantaneous wide field of view based on the minimum unit spacing between antenna elements, and forms the synthetic aperture microwave radiation image from the two-dimensional instantaneous wide field of view.

[0058] Specifically, such as Figure 2 The schematic diagram of the integrated aperture microwave radiation imaging system shows that, from left to right, the system includes an antenna array, a receiver channel array, a digital acquisition unit, a digital correlation processor, and an image inversion processor, according to the processing flow.

[0059] In this embodiment of the invention, the antenna array adopts a "cross" shaped array, which consists of four antenna arms and one intermediate unit antenna. With the number of antenna elements in a single antenna arm being N, the total number of antennas in the antenna array is 4N+1.

[0060] Each antenna element is connected to a receiver channel. The number of receiver channels is equal to the number of antenna arrays, i.e., 4N+1. Each receiver channel receives the microwave radiation signal output by the corresponding connected antenna and then performs amplification, filtering, down-conversion, intermediate frequency amplification, intermediate frequency filtering, and IQ signal demodulation in sequence through the RF front end, finally outputting the intermediate frequency signal.

[0061] The digital acquisition unit consists of multiple analog-to-digital converters (A / D). The number of A / Ds is twice the number of receiver channels (antennas), i.e., 8N+2. Each pair of A / Ds corresponds to one receiver channel and performs analog-to-digital conversion on the I-channel signal and Q-channel signal of the intermediate frequency signal output by one receiver channel, respectively.

[0062] The digital correlation processor performs pairwise correlations on all I-channel digital signals (4N+1) and Q-channel digital signals (4N+1) output by the digital acquisition unit to obtain the correlation matrix of the observed airport scene;

[0063] The image inversion processor is a real-time wide-field composite aperture microwave radiation image of the observed scene obtained by inverting the correlation matrix output by the digital correlation processor.

[0064] It should be noted that the antenna array is arranged in a cross shape, as shown below. Figure 3 As shown, the antenna array consists of four antenna arms and one intermediate antenna element. Each antenna arm has N antenna elements, and the total number of antennas in the array is 4N+1. The spacing between adjacent elements is d. x =d y =d, where a single antenna element uses a wide-beam circular horn antenna, d x d represents the spacing between adjacent elements in the X-axis direction. y This indicates the spacing between adjacent cells in the Y-axis direction.

[0065] Therefore, the synthetic aperture microwave radiation imaging system obtains a two-dimensional instantaneous wide field of view, which depends on the minimum cell spacing in the corresponding direction. Figure 4 This is a schematic diagram of the two-dimensional field of view of a composite aperture microwave radiation imaging system.

[0066] Based on the above embodiments, Figure 5 This is a flowchart illustrating the aircraft landing guidance method based on microwave radiation passive imaging provided in an embodiment of the present invention, as shown below. Figure 5 As shown, it includes:

[0067] Step 100: Acquire the synthetic aperture microwave radiation image of the scene to be observed by the synthetic aperture microwave radiation imaging system, determine the aircraft position information by the GPS positioning system, and determine the aircraft attitude information by the inertial navigation system;

[0068] Step 200: Obtain the airport 3D scene model from the 3D scene model storage and store the airport 3D scene model;

[0069] Step 300: Based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model, the integrated processor outputs real-time guidance image information and transmits the real-time guidance image information to the head-up display;

[0070] Step 400: The head-up display shows the real-time guidance image information so that the aircraft can land according to the real-time guidance image information.

[0071] Specifically, the integrated aperture microwave radiation imaging system radiates microwaves and receives microwave signals returned from the scene to be observed, processes them to obtain an integrated aperture microwave radiation image of the scene to be observed, and obtains the aircraft's position information, including longitude, latitude and altitude, through the GPS positioning system, and obtains the aircraft's attitude information, including pitch, roll and yaw, through the inertial navigation system.

[0072] Meanwhile, the 3D scene model of the airport is obtained and stored through the 3D scene model memory. The 3D scene model of the airport is reconstructed by 3D reconstruction technology from optical images of the airport scene taken from different observation angles and stored in the memory.

[0073] The integrated processor combines the aforementioned integrated aperture microwave radiation image, aircraft position information, aircraft attitude information, and stored 3D scene model, and obtains real-time guidance image information for the aircraft (pilot) through fusion and visual enhancement technologies, and then transmits the real-time guidance image information to the head-up display.

[0074] Finally, the head-up display shows the reconstructed real-time guidance image information on the screen for the pilot's reference, guiding the aircraft to approach and land.

[0075] This invention utilizes the advantages of microwave radiation passive imaging, such as strong cloud and fog penetration and low susceptibility to ground clutter, to provide aircraft with the surrounding environment for approach and landing in low-visibility weather, further improving the safety and timeliness of aircraft landing guidance in low-visibility weather.

[0076] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0077] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aircraft landing guidance system based on microwave radiation passive imaging, characterized in that, include: The integrated processor, along with an integrated aperture microwave radiation imaging system, a GPS positioning system, an inertial navigation system, a three-dimensional scene model memory, and a head-up display, all connected to the integrated processor. The integrated aperture microwave radiation imaging system acquires integrated aperture microwave radiation images of the scene to be observed; The GPS positioning system provides aircraft location information; The inertial navigation system provides aircraft attitude information; The 3D scene model storage device stores the 3D scene model of the airport; The integrated processor generates real-time guidance image information based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model; The head-up display shows the real-time guidance image information; The integrated aperture microwave radiation imaging system includes an antenna array, a receiver channel array, a digital acquisition unit, a digital correlation processor, and an image inversion processor connected in sequence. The antenna array outputs microwave radiation signals; The receiver channel array receives the microwave radiation signal and generates an intermediate frequency signal; The digital acquisition unit performs analog-to-digital conversion on the intermediate frequency signal and outputs a digital signal. The digital correlation processor generates a correlation matrix of the scene to be observed based on the digital signal; The image inversion processor inverts the correlation matrix of the scene to be observed and outputs the composite aperture microwave radiation image; The antenna array includes multiple antenna elements, which together form a cross-shaped antenna array. The cross-shaped antenna array includes four antenna arms and a central antenna element. Each antenna arm includes N antenna elements, and the antenna array includes 4N+1 antenna elements. All antenna elements are equally spaced, with the spacing between adjacent elements being [missing information]. Each antenna element employs a wide-beam circular horn antenna. Indicates the spacing between adjacent elements in the X-axis direction. Indicates the spacing between adjacent elements in the Y-axis direction; The antenna element is a preset wide-beam circular horn antenna; The receiver channel array includes 4N+1 receiver channels, and each receiver channel is connected to a single antenna element. The single receiver channel sequentially amplifies, filters, downconverts, amplifies, filters, and demodulates the microwave radiation signal through the radio frequency front end, and outputs the intermediate frequency signal. The digital acquisition unit includes 8N+2 analog-to-digital converters, with each pair of analog-to-digital converters corresponding to one receiver channel; Each pair of analog-to-digital converters performs analog-to-digital conversion on the I-channel and Q-channel signals of the intermediate frequency signal output from one receiver channel, respectively, to obtain the digital signal; The digital correlation processor performs pairwise correlation calculations on the 4N+1 I-channel signals and 4N+1 Q-channel signals output by the digital acquisition unit to obtain the correlation matrix of the scene to be observed. The image inversion processor determines a two-dimensional instantaneous wide field of view based on the minimum element spacing between antenna elements, and forms the synthetic aperture microwave radiation image from the two-dimensional instantaneous wide field of view.

2. The aircraft landing guidance system based on microwave radiation passive imaging according to claim 1, characterized in that, The integrated processor determines the aircraft's position information as the observation position and the aircraft's attitude information as the observation azimuth, and fuses the integrated aperture microwave radiation image with the airport's three-dimensional scene model. It then uses image fusion and visual enhancement to construct the real-time guidance image information.

3. The aircraft landing guidance system based on microwave radiation passive imaging according to claim 1, characterized in that, The airport 3D scene model is obtained by 3D reconstruction of optical images of the airport scene from different observation angles.

4. An aircraft landing guidance method based on microwave radiation passive imaging, used to execute the aircraft landing guidance system based on microwave radiation passive imaging as described in any one of claims 1 to 3, characterized in that, include: The integrated aperture microwave radiation image of the scene to be observed is acquired by the integrated aperture microwave radiation imaging system, the aircraft position information is determined by the GPS positioning system, and the aircraft attitude information is determined by the inertial navigation system. The airport 3D scene model is obtained from the 3D scene model memory and stored. The integrated processor outputs real-time guidance image information based on the integrated aperture microwave radiation image, the aircraft position information, the aircraft attitude information, and the airport 3D scene model, and transmits the real-time guidance image information to the head-up display; The head-up display shows the real-time guidance image information so that the aircraft can land based on the real-time guidance image information.

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